We appreciate the efforts of the Standards Board in implementing tougher standards in the last two year to prevent silicosis among California fabrication workers. The recent passage of SB 20( Occupational safety: high-exposure trigger tasks on artificial stone- approved by Governor Newsom October 13, 2025) is also another step to grapple with the rising number of silicosis cases. SB 20 reinforces the current approach of education and enforcement by requiring attestation of worker training, making serious violations of the silica standard a rebuttable presumption, and enhancing outreach, education, technical assistance, and reporting of silicosis cases.
However, the evidence is now clear that engineered stone containing crystalline silica is too toxic to fabricate and install safely, and education and enforcement alone will not be sufficient to curtail the escalating occupational health emergency caused by this product.
As physicians who specialize in occupational diseases, we expect the silicosis health epidemic to continue unless there is expedited Cal / OSHA rulemaking that effectively prohibits all fabrication and installation( processing that generates dust) of engineered stone. This action is necessary to protect these workers and their families from a deadly disease and to open the market for safer products, which are already commercially available.
As you may know, the most effective approach to preventing occupational disease is elimination of hazardous products and substitution with safer and less toxic materials.
Fortunately, there are many safer substitutes currently available that can be used as alternatives to engineered stone containing crystalline silica. Manufacturers of engineered stone( including those with countertop product lines containing crystalline silica) are currently offering safer alternative products in Australia that are crystalline silica-free, and which retain the same quality, look and feel of engineered stone containing crystalline silica. These products emerged in the market in response to Australia’ s July 1, 2024 ban on engineered stone containing crystalline silica. They are commonly composed of amorphous( not crystalline) silica and are manufactured in a process similar to that of engineered stone. 1 It is important to note that crystalline silica causes silicosis; amorphous silica is a different substance and is much safer. A recent Australian government evaluation confirmed that the prohibition is largely working as expected, creating a rapid change in the market and new opportunities for safer products, while protecting workers from exposure to respirable crystalline silica.
If the Standards Board adopts the Australian approach and implements revisions to § 5204 that prohibit all fabrication and installation tasks on all engineered stone that contain more that 1 % crystalline silica, it is highly likely that these safer products will be made immediately available in the California market, without significant economic consequences for fabrication businesses and their workers. IKEA has already removed engineered stone from its U. S. retail locations. Indeed, responsible fabrication businesses will likely experience no additional
1
Unlike crystalline silica, which has long been known to toxic and carcinogenic, amorphous silica is relatively less toxic and is regulated in the workplace as a nuisance dust. One of world’ s leading developer of engineered stone( Breton) offers a crystalline silica-free aggregated manufacturing plant with the same aesthetic and technical features( see https:// breton. it / en _ na).
2